000 AXNT20 KNHC 130557 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST THU DEC 13 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 5N25W 5N40W 3N51W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM N OF THE AXIS BETWEEN 34W-38W AND WITHIN 180 NM S OF THE AXIS BETWEEN 24W-29W. SCATTERED MODERATE TO STRONG IS FROM 7N-13N BETWEEN 45W-58W AND FROM 4N-6N E OF 12W. DISCUSSION... GULF OF MEXICO... A COLD FRONT HAS WORKED ITS WAY INTO THE FAR NW CORNER OF THE REGION EXTENDING FROM THE TEXAS/LOUISIANA BORDER TO NRN MEXICO NEAR 25N97W. CONSIDERABLY COOLER AND DRIER AIR IS FILTERING IN BEHIND THE FRONT. DOPPLER RADAR SHOWS A NARROW LINE OF SCATTERED SHOWERS WITHIN 60 NM OF THE BOUNDARY. ELSEWHERE...SFC RIDGING CONTINUES TO DOMINATE THE PATTERN EXTENDING WSW FROM A 1026 MB HIGH S OF BERMUDA. LOW-LEVEL ELY FLOW IS ADVECTING ISOLATED TO SCATTERED SHOWERS FROM THE ATLC INTO THE FLA STRAITS. IN THE MID AND UPPER LEVELS...A RIDGE HAS BEEN FAIRLY STATIONARY DIRECTLY OVERHEAD ALLOWING THE FLOW ALOFT TO BE LIGHT AND ATMOSPHERE VERY STABLE. A SHORTWAVE IS FURTHER NW OVER THE CENTRAL U.S. PROVIDING SUPPORT FOR THE COLD FRONT MENTIONED. THIS TROUGH ...HOWEVER...IS EXPECTED TO FLATTEN OUT LATER TODAY LIMITING THE PROGRESS OF THE COLD FRONT. THE NEXT TROUGH/FRONT WILL BE MUCH STRONGER ENTERING THE NW CORNER EARLY SAT. CARIBBEAN SEA... THE LAST ADVISORY WAS ISSUED ON T.D. OLGA EARLIER THIS EVENING. THE REMNANTS ARE CURRENTLY CENTERED JUST N OF JAMAICA NEAR 19N78W MOVING W 10 KT OR SO. THE CIRCULATION IS STILL EASILY IDENTIFIABLE ON NIGHT CHANNEL VIS IMAGES BUT CONVECTION IS NEARLY ABSENT NEAR THE CENTER AND THERE ARE ONLY A FEW BANDS N OF THE SYSTEM OVER ERN CUBA AND NEAR THE BAHAMAS. FAIRLY DENSE LOW TO MID LEVEL CLOUDS AND SHALLOWER SHOWER/TSTM ACTIVITY IS MOSTLY TO THE N AND E OF THE LOW-LEVEL CENTER N OF 17N BETWEEN 71W-78W. ONLY ISOLATED SHOWERS ARE AHEAD OF THE LOW N OF 17N BETWEEN 78W-83W. SIMILAR ISOLATED ACTIVITY IS E OF 70W ENHANCED BY AN INCREASE IN THE ELY TRADES. ATLANTIC OCEAN... BANDS OF SHOWERS/TSTMS...ASSOCIATED WITH THE REMNANTS OF T.D. OLGA...IS AFFECTING PORTIONS OF THE SW ATLC INCLUDING THE BAHAMAS S OF 25N BETWEEN 70W-78W. LIGHTNING DATA DEPICTS THE STRONGEST BANDS JUST N OF THE COAST OF CUBA AND NEAR THE N SHORE OF THE HISPANIOLA TO THE S CENTRAL BAHAMAS. THE REMAINDER OF THE DISCUSSION AREA IS DOMINATED BY MODERATE TO STRONG SFC RIDGING SUPPORTED BY A 1026 MB HIGH LOCATED SE OF BERMUDA NEAR 31N63W AND A 1024 MB NEAR 36N39W. THERE IS A SLIGHT WEAKNESS IN THE RIDGE E OF ABOUT 40W DUE TO A DISSIPATING COLD FRONT THAT EXTENDS TO 29N42W AND A LARGE INVERTED TROUGH NEAR THE AFRICAN COAST N OF 18N. A 1014 MB LOW HAS DEVELOPED ALONG THE TROUGH AXIS NEAR 25N17W AS NOTED IN A RECENT ASCAT PASS. THE MID AND UPPER PATTERN CONSISTS OF A LONGWAVE RIDGE/TROUGH IN THE SUBTROPICS WITH A SERIES OF EMBEDDED SHORTWAVES E OF ABOUT 50W. THE ONLY AREA OF ORGANIZED CLOUDINESS IN THE SUBTROPICS IS IN THE FAR E PORTION N OF 22N E OF 17W ASSOCIATED WITH DIFFLUENCE ALOFT TO THE SE OF AN UPPER LOW NEAR 30N21W AIDED BY SFC TROUGH NEAR THE AFRICAN COAST. IN THE TROPICS...THE FLOW ALOFT IS FAIRLY ZONAL. STRONG WINDS S OF 13N AND A SLIGHTLY DIFFLUENT PATTERN IS ENHANCING SCATTERED MODERATE TO STRONG CONVECTION N OF THE ITCZ BETWEEN 45W-59W. DEBRIS MOISTURE HAS SPREAD WELL E TO AFRICA MAINLY S OF 15N. $$ CANGIALOSI